This invention relates generally to catheters and more particularly to heart catheters for use in pulmonary arteriography.
Pulmonary catheterization for purposes of arteriography is becoming well known in the field of pulmonary care. In this procedure, generally, a catheter formed of an elongated length of flexible tubing is fed into the patient's body through a vein to the location of interest. Thereafter, a radiopaque liquid is injected and conveyed to the site through the distal end of the catheter during which time x-rays are taken to observe the blood flow and tissue structure therearound.
One aspect of this arteriography is with respect to the main, right, left and secondary pulmonary arteries which connect the right ventricle of the heart and the lungs. The widely accepted technique for pulmonary arteriography (as it is known) is via the femoral approach wherein a catheter if first inserted into the patient's body through a vein in a lower limb and fed through the inferior vena cavae, into the right atrium of the heart, then through the tricuspid valve and into the right ventricle, then through the pulmonary semilunar valve and into the main or right or left pulmonary artery. Thereafter, the radiopaque fluid is injected through the catheter for disbursement within the selected portion of the pulmonary artery.
Because of the shape of the heart in relation to the inferior vena cavae, the distal end of the catheter, first moving upwardly into the right atrium, must be then curved slightly downwardly to pass through the tricuspid valve and into the right ventricle, and then must be curved upwardly again to pass through the pulminary semilunar valve. Of no inconsequential risk, to facilitate these necessary gyrations in conjunction with the femoral approach to pulmonary arteriography, in addition to the catheter tubing size required to be larger and more rigid than ideally necessary for the effusion of radiopaque liquid, a rigid guide wire is alternately inserted and removed through portions of the catheter to further enhance the rigidity and shape necessary to effect prior placement and movement of the distal end of the catheter within the pulmonary artery as desired. Further, pulmonary arteriography can, at times, be a lengthy and tedious procedure, and is usually performed on patients who are critically ill. Many times under these circumstances, the heart rhythm is disrupted because of these required strenuous gyrations of the catheter and, in some instances, the interior wall of the heart is bruised and occasionally pierced. A catheter which provides swift placement for selective arteriography with a minimum of complication is therefore desirable.
In an editorial by J. A. Grollman entitled "Pigtail Catheters In Pulmonary Angiography" appearing in Catheterization and Cardiovascular Diagnosis, Volume 1, Number 10, Pages 389-391, Dr. Grollman discusses variations of straight catheters which include a pigtail contour at their distal ends. This structure, utilized in conjunction with conventional catheters and applied via the femoral approach is, according to Dr. Grollman, intended to relieve many, if not all, of the above described shortcomings of pulmonary arteriography. Three variations of pigtail catheters are discussed, two of which include pigtail structure at the distal end which is curved in the opposite direction to at least one of the other curvatures formed along the length of the catheter tubing. However, all of these structures there presented are adapted primarily to facilitate the femoral approach to pulmonary arteriography.
A primary advantage in inventing a catheter adapted to be utilized in conjunction with an antecubital approach to pulmonary arteriography is in taking advantage of the geometry between the superior vena cavae, the right atrium and tricuspid valve. Applicants have invented such an improved catheter having a tight pigtail contour formed adjacent its distal end, which invention facilitiates an antecubital approach to pulmonary arteriography and also facilitates the reduction in both diameter and rigidity of the catheter tubing to further reduce the jeopardy into which the patient's heart is placed during such procedures. Additionally, dimensional and contour variations of applicants' invention are provided which are adapted to accommodate patients with enlarged hearts.